Greatly refactored the docs index to allow for more efficient use by power...

Greatly refactored the docs index to allow for more efficient use by power users, while staying clean for new users. It no longer takes four clicks to get to the list of default template filters.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@9490 bcc190cf-cafb-0310-a4f2-bffc1f526a37